This page of the guide to Biomutant contains a walkthrough of the side quest The Shellhorn Friend. We have described everything you need to do in order to complete the quest and earn the rewards.
Starting the quest
How to start: Talk to a man in town - Flibberdit.
Reward: 100 XP.
Talk to the man in the tower. He will mention a friend of his who has a problem with his shellhorn.